Stream: git-wasmtime

Topic: wasmtime / PR #6045 x64: Elide more uextend with extractlane

Wasmtime GitHub notifications bot (Mar 17 2023 at 15:53):

alexcrichton opened PR #6045 from more-extend-elision to main:

I've confirmed locally now that pextr{b,w,d} all zero the upper bits of the full 64-bit register size which means that the extractlane operation with a zero-extend can be elided for more cases, including 8-to-64-bit casts as well as 32-to-64.

This helps elide a few extra movs in a loop I was looking at and had a modest corresponding increase in performance (my guess was due to the slightly decreased code size mostly as opposed to the removed movs).

<!--

Please ensure that the following steps are all taken care of before submitting
the PR.

• [ ] This has been discussed in issue #..., or if not, please tell us why
  here.

• [ ] A short description of what this does, why it is needed; if the
  description becomes long, the matter should probably be discussed in an issue
  first.

• [ ] This PR contains test cases, if meaningful.

• [ ] A reviewer from the core maintainer team has been assigned for this PR.
  If you don't know who could review this, please indicate so. The list of
  suggested reviewers on the right can help you.

Please ensure all communication adheres to the code of conduct.
-->

Wasmtime GitHub notifications bot (Mar 17 2023 at 15:56):

abrown submitted PR review.

Wasmtime GitHub notifications bot (Mar 17 2023 at 15:56):

abrown submitted PR review.

Wasmtime GitHub notifications bot (Mar 17 2023 at 15:56):

abrown created PR review comment:

Not sure you wanted to check this one in.

Wasmtime GitHub notifications bot (Mar 17 2023 at 15:57):

alexcrichton updated PR #6045 from more-extend-elision to main.

Wasmtime GitHub notifications bot (Mar 17 2023 at 15:57):

alexcrichton submitted PR review.

Wasmtime GitHub notifications bot (Mar 17 2023 at 15:57):

alexcrichton created PR review comment:

Whoops, indeed!

Wasmtime GitHub notifications bot (Mar 17 2023 at 15:57):

alexcrichton has enabled auto merge for PR #6045.

Wasmtime GitHub notifications bot (Mar 17 2023 at 16:52):

alexcrichton merged PR #6045.

Last updated: Dec 23 2024 at 12:05 UTC